Mr Trump was asked about the subject of his civil lawsuit, which began on Monday, in which he, along with his adult sons, is accused of defrauding banks and insurers by overvaluing properties in the Trump Organization portfolio by billions of dollars.
The lawsuit is being brought by the office of Ms James, though New York Supreme Court Judge Arthur Engoron – who is overseeing the trial – has already determined Mr Trump is liable for fraud.
During his appearance in Santa Monica, which took place ahead of the lawsuit, Mr Trump was asked why he lied about the square footage of his Trump Tower property in New York.
The former president initially turned on the reporter, snapping back: “Why do you have to read that [question]? Can’t you remember it?”
He then launched into a tirade about Ms James – who he branded as “fake” and “racist” without explanation – and Judge Engoron.
“Just so you know, my financial statements are much lower than the actual net worth, this judge and your fake attorney general from New York, who is driving business out, who’s letting murderers run all over the city,” he said.
“They don’t do anything to murderers that are running all over the city. The attorney general is a racist, Letitia James – she should be ashamed of herself.”
During the heated exchange with reporters, the two young girls who had stood with Mr Trump for photos looked somewhat uncomfortable and tried to get out of the line of fire.
Mr Trump’s civil lawsuit continued on Tuesday, with the former president vowing to testify during the trial “at the appropriate time”
He previously claimed that he had had a “good day” in court on Monday, and shared a bizarre fake court sketch – depicting himself sitting next to Jesus Christ.